In some wireless communication systems, user equipments (UEs) wirelessly communicate with one or more transmit/receive points (TRPs) to send data to the TRPs and/or receive data from the TRPs. A wireless communication from a UE to a TRP is referred to as an uplink communication. A wireless communication from a TRP to a UE is referred to as a downlink communication.
A UE may be served by a serving cell that includes one or more TRPs. The UE may communicate with the one or more TRPs to send uplink communications and receive downlink communications.
Resources are required to perform uplink and downlink communications. For example, a TRP may wirelessly transmit data, such as a transport block (TB), to a UE in a downlink communication at a particular frequency and for a particular duration of time. The frequency bandwidth and time duration used are examples of resources.
Resources are also required to transmit reference signals in a wireless communication system. Reference signals are pre-defined signals, known to both the transmitter and the receiver, that can be used to measure the state of a channel. Information regarding the measured state of the channel may be referred to as channel state information (CSI). The reference signal used to generate CSI may be referred to as a channel state information reference signal (CSI-RS). CSI may include, for example, information related to scattering, fading, power decay and signal-to-noise ratio (SNR) in the channel. The CSI may be reported back to the CSI-RS transmitter in the form of a measurement report. The CSI may then be used to adapt uplink and/or downlink transmissions based on the measured state of the channel.
Synchronization signals are used to coordinate the operation of transmitters and receivers in the time domain. In some wireless communication systems, synchronization signal blocks (SSBs) are transmitted by a TRP in order for a UE to determine the frame timing at the TRP. SSBs may also be used by a UE to determine the quality of reception from serving and neighboring cells for mobility purposes. An SSB may be associated with a specific CSI-RS.
A network typically configures the resources associated with reference signals and/or synchronization signals. For example, time and frequency resources may be configured for transmitting CSI-RSs from a TRP to a UE, reporting measurements from the UE back to the TRP, and transmitting SSBs from the TRP to the UE. These resource configurations are signaled to the UE using a signaling message in order for the UE to more reliably receive the CSI-RSs and SSBs. The UE then transmits a signaling message that includes the measurement reports. A need exists for signaling designs that aim to provide more flexible and efficient signaling of CSI-RS resource configurations and measurement reports.